Chemistry, polymer dynamics and mechanical properties of a two-part polyurethane elastomer during and after crosslinking. Part I: dry conditions

Zimmer, Bettina; Nies, Christophe; Schmitt, C.; Possart, Wulff

doi:10.1016/j.polymer.2017.03.020

Cited by 44 publications

(21 citation statements)

References 34 publications

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“…1,[22][23][24][25][26][27][28][29] In this line, Guan et al designed and synthesized a unique uorescent surfactant (TPE-DTAB), which combined both the properties of the aggregation-induced emission (AIE) and amphilicity which together were used to image the macrodispersion of the layered double hydroxide llers (montmorillonite) in the polymer matrix. 30 Wang's group also visualized the entire gelation process of chitosan (CS) by the synthesized AIE uorogenic probe, that is, tetraphenylethene-labelled chitosan (TPE-CS).…”

Section: 21mentioning

confidence: 99%

Studying a novel AIE coating and its handling process via fluorescence spectrum

Yao

Wang

et al. 2017

RSC Adv.

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For polymer materials, both their compositions and preparation process greatly influence their service performance. Thus, the sound understanding of the relationship between materials' preparation processes and their properties is paramount. However, current research methods are partially limited due to the absence of a direct testing method to track the entire process, e.g. synthesizing, curing, ageing, and so on. With the ability for real-time sensitive characterization, fluorescence spectroscopy may be applied in testing polymer materials' performance. Here, we synthesized a novel aggregation induced emission (AIE) resin named TPE-EPOXY resin and prepared an AIE coating based on it.According to restriction of intramolecular rotation (RIR) mechanism, the preparation, curing, and aging processes for the AIE polymer resins & coatings could be studied with real-time observation. In addition, their properties could also be studied systematically. The results in this paper pave a good way to understand the relationship between the internal structure and the properties of polymer materials.Moreover, the prepared AIE polymer resins has a potential to expand the application fields of the AIE mechanism.

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Section: 21mentioning

confidence: 99%

Studying a novel AIE coating and its handling process via fluorescence spectrum

Yao

Wang

et al. 2017

RSC Adv.

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“…Polyurethane foam has an ageing effect that induced changes in its properties . Especially, as shown in the compression performance assessment for 50 wt%, if a certain amount of HFC‐365mfc is exceeded, performance is dramatically degraded.…”

Section: Resultsmentioning

confidence: 99%

Synthesis of Polyurethane Foam Considering Mixture Blowing Agents for Application to Cryogenic Environments

Son

Kim

Choi

et al. 2019

Macro Materials & Eng

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Polyurethane foams, which are among the most widely used insulating materials, are generally fabricated by the chemical reaction between isocyanate and polyol‐containing chemical additives and blowing agents. Recently, many kinds of blowing agents have been used for the fabrication process of polyurethane foam, such as hydrochlorofluorocarbons (HCFCs) and chlorofluorocarbons (CFCs). However, issues have continuously arisen regarding the destruction of the ozone layer due to these compounds. In the present study, polyurethane foams are manufactured using a mixture of water blowing agents and hydrofluorocarbons (HFC‐365mfc). These samples are subjected to mechanical tests to investigate the effects of the blowing agents on the mechanical properties of the polyurethane foam within a temperature range of 25 to −163 °C. In addition, thermal and microstructural investigations are conducted depending on the content of the HFC‐365mfc. From the scanning electron microscopy observations, the sizes of the structure cells and the windows are found to decrease with the increase in HFC‐365mfc content. In addition, from the Fourier transform‐infrared spectroscopy observations, the chemical bonds that affect mechanical performance are found to be more distributed with the increase in HFC‐365mfc content.

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“…Some characteristics polyol bands were assigned in Figure 1(a): the band at 3450 cm -1 indicates the presence of hydroxyl groups; that band at 3008 cm -1 is attributed to the (CH) stretching; 2924 cm -1 to methylene asymmetric stretching ν as (CH 2 ) and 2854 cm -1 to the methylene symmetrical stretching ν ss (CH 2 ) [3,25,26]. The hydroxyl band intensities presented in Figure 2 [3,[26][27][28]. In addition, hydroxyl characteristic bands might also be identified at 1048 cm-1 (primary hydroxyl stretching) and 1096 cm-1 (secondary hydroxyls stretching) [29].…”

Section: Resultsmentioning

confidence: 99%

“…For a quantitative analysis of curing kinetics, isocyanate consumption (% NCO) was calculated using equation (1) [28]: (1) where I Ref is the intensity of the reference band (2924 cm −1 assigned to ν-CH 2 asymmetric stretching), I NCO is the intensity of the isocyanate band (2263 cm -1 ), t cure is the current reaction time, and t 0 is the reaction time of the first measurement spectrum. The isocyanate consumption was plotted as a function of the curing time in Figure 4.…”

Section: Resultsmentioning

confidence: 99%

“…It can be observed in all cases that, initially the isocyanate consumption occurs at higher rates up to 10 h of reaction, followed by a considerable reduction in the polymerization rate. Higher initial polymerization rates might be related to high concentration of free reactive groups, which decreases during the polymerization reaction, thus decreasing the reaction rate [28].…”

Section: Resultsmentioning

confidence: 99%

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Lithium catalyst concentration influence on bio-polyols structure and polyurethane adhesives properties

2019

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Polyol structure can be affected by the catalyst used for its synthesis and may affect the curing kinetics and mechanical strength of the final polyurethane (PU). This work aimed to study the influence of catalyst concentration on the structure of bio-based polyols and on the final properties of the polyurethane adhesive obtained from these polyols. Polyols were investigated by Fourier transform infrared (FTIR), gel permeation chromatography (GPC) and hydroxyl index analysis, with the purpose of investigating the polyols chemical state after the synthesis. Results suggest that higher catalyst concentration led to polyols with higher hydroxyl index and other differences in the polyols structure. The influence of the catalysts concentration on the cure kinetics of the polyurethanes was verified using the Fourier transform infrared (FTIR). In addition, peel strength of PU adhesives was obtained by increasing catalyst concentration on polyol synthesis.

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Chemistry, polymer dynamics and mechanical properties of a two-part polyurethane elastomer during and after crosslinking. Part I: dry conditions

Cited by 44 publications

References 34 publications

Studying a novel AIE coating and its handling process via fluorescence spectrum

Studying a novel AIE coating and its handling process via fluorescence spectrum

Synthesis of Polyurethane Foam Considering Mixture Blowing Agents for Application to Cryogenic Environments

Lithium catalyst concentration influence on bio-polyols structure and polyurethane adhesives properties

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